Murkowski, a write-in candidate who is shaping up to be stiff competition for Miller, has been boosted by $1 million that Alaskans Standing Together has planned to spend on her behalf so far, including on advertisements that are critical of the GOP nominee.

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Now Miller is charging that the group's relationship with Murkowski is inappropriate, saying the senator is "bought and paid for" by the Alaska Native corporations that make up Alaskans Standing Together. Miller's complaint alleges that nine of the benefactors of the Super PAC are in violation of federal law because they contract with the federal government.

"Even by Washington, D.C., standards, the level of corruption shown by Alaskans Standing Together and Lisa Murkowski is shocking," said Miller. "Their efforts to preserve the status quo and reelect their 'bought and paid for' senator are not even bound by the law. The Alaskan Native Corporations have reaped billions from questionable set-asides and federal contracting programs, and Sen. Murkowski has fought efforts to reform them. We now know why."

The complaint touches on fresh legal ground, since a U.S. Supreme Court ruling earlier this year allowed corporations to make unlimited independent expenditures in political campaigns, thereby creating corporate-sponsored Super PACs like Alaskans Standing Together.

The complaint also underscores how competitive the race has become, with a recent CNN/Time poll showing Murkowski and Miller in a dead heat. Miller's objection comes on the heels of one of his roughest weeks to date in the campaign, thanks to a Sunday evening incident in which one of his hired bodyguards arrested a reporter after a campaign event.

The chairman of Alaskans Standing Together, Will Anderson, released a statement that said his group was abiding by the law according to the Supreme Court's Citizens United ruling and an FEC advisory from 1998. According to Anderson, the 1998 advisory opinion allows for the parent companies of federal contractors to donate if they have other sources of revenue.

"Joe Miller likes to wrap himself in the U.S. Constitution while trampling on it at the same time," Anderson said in the statement. "First, his bodyguards handcuff a reporter for asking questions at a public event. Now he is trying to handcuff the Alaska Native community from having a voice in this campaign while he brings in hundreds of thousands of dollars from groups outside Alaska."

The complaint was prepared by the firm of Thomas Van Flein, who has also served as Sarah Palin's chief counsel. Palin supported Miller from the start of his campaign and has been highly critical of Murkowski's write-in bid since she launched it shortly after losing the GOP primary.